Flexible-shaft connection.



G. RENSCH.

FLEXIBLE SHAFT CONNECTION.

APPLICATION min APR. 30. 1913.

1 206,029. I Patented Nov. 28,1916.

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, UNITED STATES PATENT onrron.

GEOIRG RENSCH, OF BERLIN, GERMANY.

FLEXIBLE-SHAFT CONNECTION.

Application filed April 80, 1913.

To all whom it may concern:

Be it known that I, Gnone RENsoH, engineer, subject ofthe King of Prussia, residing at Berlin, in the Kingdom of Prussia and German Empire, have invented certain new and useful Improvements in Flexible- Shaft Connections, of which the following is a specification.

The present invention relates to a further development and improvement of the subject matter ofmy previous application for patent Ser. No. 700,905.

In the arrangement according to the said application a flexible protective casing is provided around the flexible shaft, coupled direct to the axis without any intermediate gearing, the said casing being supported with its one end on the axis or its extensions. With this arrangement in practice the disadvantage has been observed, that in consequence of the unavoidable vibrations imparted to the said protective casing it will break close to the part supported on the axis. The reason for this is in the fact that the individual coils of the said protective casing engage in a hinge-like manner in each other, and when the casing is bent, they bear tightly and under a certain pressure against each other, so that in consequence of the unavoidable vibration a great friction is produced at such points, which friction will, after a more or less lengthy period lead to a fracture. All attempts to obviate this evil have hitherto failed.

According to the present invention this disadvantage is avoided by leaving the flexible shaft, which is coupled, the same as in the above mentioned original application, direct to the axis or its extension, uncovered by the said protective casing along its lowermost portion. The casing is carried down as far as possible, and leaves only so much of the flexible shaft uncovered, as is absolutely indispensable for allowing for the free play of the locomotive springs. Preferably the casing is continued'so far down, that the uncovered portion of the flexible shaft, which at the point at which it is coupled to the axis, lies in the direction of the latter and must thence be brought into an almost vertical direction, forms approximately the quadrant of a circle. The lower end of the casing is rigidly connected to the frame of the locomotive by means of a bracket or the like, so as to reduce the shaking of the flexible shaft to a minimum.

Specification of Letters Patent.

Patented Nov. 28, 1916.

Serial N 0. 764,593.

In place of the coiled protective tube casing preferably a metal tube is employed, which is bent in a manner corresponding to the construction of the respective locomotive. The lower end of the protective tube is preferably flared like a trumpet. The point at which it is secured or its lower end is preferably arranged directly above the axis. By this arrangement it is obtained, that the play of the springs will only exert a pull in the direction of the flexible shaft, without causing the same to strike or bear against the walls of the lower end of the protective tube. \Vhen, now, the lower end of the flexible shaft is left bare, it must be made in such a manner, that it is impossible for it to kink or to sag too freely, and it is therefore formed of a material having a certain initial degree of rigidity. Therefore link-chains or the like, as they were hitherto used for the completely covered flexible shaft cannot be used for its uncovered part. It has however been found practical to make the uncovered part of the flexible shaft in the form of a Bowden shaft, while the part within the protective covering or tube, leading up to the tachometer is made as link-shaft. By Bowden shaft as the term is used herein, is meant that type of flexible shafting which is formed of a plurality of overlying layers of wire, each layer comprising a plurality of strands and being twisted or wound in the opposite direction to the underlying layer. When, however, the lower end is made as a Bowden shaft or the like, and particularly by reason of the strong design which is necessary in this case, the disadvantage is observed that the speed transmission becomes irregular owing to the torsional elasticity. This irregularity in the speed transmission will have to be remedied, and this may be obtained by the other part of the flexible shaft which is within the protective covering or tube being made in such a manner, that it will counteract such irregularity, so that the shaft, as a whole, will in itself, compensate of the other.

Inorder to avoid the flexible shaft falling down in case the same or the coupling with the tachometer within the protective covering should break, an arrangement is provided at the lower end of the protective tube, which will catch the same. This arrangement consists of a ring fitted in the tube and a corresponding collar or head on the flexible shaft, which will abut against and ride on said ring in case the shaft should fall.

In the accompanying drawing the invention is exemplified in three figures.

Figure 1 is a diagram showing the arrangement of a tachometer coupled directly to the wheel axle, in side view. Fig. 2 is a view seen at a right angle to Fig. 1. Fig. 3 is a part of the flexible shaft on an enlarged scale, partly in view and partly in section.

This modification difiers from the one shown in Figs. 1 and 2 in that the flexible shaft is here connected tothe axle of a driving wheel instead of a driven wheel, namely by means of an auxiliary crank secured to the crank proper.

In the said drawing 1 is the wheel axle, to which the flexible shaft 2 is connected. 3 is the frame of the locomotive. 4: is the tachometer, which is arranged in the drivers cabin. 5 is the bracket, rigidly attached to the frame, to which the lower end of the protective tube for the flexible shaft is secured. The protective tube is indicated by the numeral 6, and within this tube a ring 7 is provided, which may be secured in position by means of screws or the like. Above this ring a bead or collar 8 is provided on the flexible shaft.

The lower link of the chain is provided With a special neck or collar 8 which is attached to the flexible shaft 2. On normal operation, the collar 8 is not connected with the ring 7 located therebeneath. If the chain breaks, then the lower portion which is broken falls down, and the collar 8 will seat itself on the ring 7, and prevent the shaft from falling to the ground.

lVhat I claim and desire to secure by Letters Patent is:

1. A driving shaft for tachometers, comprising in combination, a jointless flexible shaft section disposed to transmit motion from a horizontal axis to a vertical axis, a linked flexible shaft section comprising a series of links connected to the vertical portion of said jointless flexible shaft section, and a protective housing for said linked flexible shaft section.

2. A driving shaft for tachometers, comprising in combination, coupled shaft sections forming a continuous shaft, one of the shaft sections being formed of jointless shafting material and being arranged to transmit motion from a horizontal axis to a vertical. axis and the remaining section being formed of a series of links adapted to avoid irregularities due to torsional elasticity in the structure.

3. A driving shaft for tachometers, comprising in combination, coupled shaft sections forming a continuous shaft, one section consisting of ointless shafting material and disposed to constitute a quadrant-like bend for the purpose of transmitting motion from a horizontal axis to a vertical axis, and the remaining section consisting of a series of links free of torsional elasticity, and a protective housing covering the shaft, but leaving the quadrant-like bend free of covering.

4. A driving shaft for tachometers, comprisingin combination, a jointless flexible shaft section disposed to transmit motion from a horizontal axis to a vertical axis, a linked flexible shaft section comprising a series of links connected to the vertically disposed portion of the j ointless shaft section, a portective housing covering the linked flexible shaft section and the connec tion between the two sections, and means for engaging and supporting a link upon the accidental breaking of a link for preventing said sections from falling apart.

In testimony whereof I have affixed my signature in presence of two Witnesses.

GEORG RENSCH. lVitnesses IVOLDEMAR HAUr'r, HENRY HASPER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. 0. 

